Need help please with Crowdsale contract and Chainlink pricefeed

Smart Contracts
1

Hi, i try to merge the OpenZeppelin AllowanceCrowdsale contract with a Chainlink Pricefeed but i cant get it to work. On deploy in Remix i get this error code:

BlockquoteGas estimation errored with the following message (see below). The transaction execution will likely fail. Do you want to force sending?
Internal JSON-RPC error. { "code": -32000, "message": "execution reverted" }

I know that the error is in line 14: uint256 myrate = uint256(getRate());
becuase if i comment it out and set myrate static like in line 15 i can deploy the contract.

I am new to Solitity so i dont even know if my contract will work at all like it is designed. Would it be better launch 2 contracts? one for calculating the "myrate" based on the pricefeed, and calling the function from my Crowdsale contract?
Or how can i get this to work? Any help is very much appreciated!

My contract:

// SPDX-License-Identifier: MIT
pragma solidity ^0.5.5;

import "https://github.com/OpenZeppelin/openzeppelin-contracts/blob/release-v2.5.0/contracts/crowdsale/Crowdsale.sol";
import "https://github.com/OpenZeppelin/openzeppelin-contracts/blob/release-v2.5.0/contracts/token/ERC20/ERC20.sol";
import "https://github.com/OpenZeppelin/openzeppelin-contracts/blob/release-v2.5.0/contracts/crowdsale/emission/AllowanceCrowdsale.sol";
import "https://github.com/OpenZeppelin/openzeppelin-contracts/blob/release-v2.5.0/contracts/crowdsale/validation/PausableCrowdsale.sol";
import "@chainlink/contracts/src/v0.5/interfaces/AggregatorV3Interface.sol";

contract Swaplast is Crowdsale, AllowanceCrowdsale, PausableCrowdsale {

    AggregatorV3Interface internal priceFeed;
    
    uint256 myrate = uint256(getRate());
    //uint256 myrate = 10;
    
    /**
     * Network: Binance Smart Chain Testnet
     * Aggregator: BNB/USD
     * Address: 0x2514895c72f50D8bd4B4F9b1110F0D6bD2c97526
     */
    constructor(
    //uint256 _rate,
    address payable _wallet,
    ERC20 _token,
    address _tokenWallet
  ) 
    
    Crowdsale(myrate, _wallet, _token)
    AllowanceCrowdsale(_tokenWallet)
    public {
        priceFeed = AggregatorV3Interface(0x2514895c72f50D8bd4B4F9b1110F0D6bD2c97526); 
    }

    function getRate() public view returns (int) {
        (
            uint80 roundID,
            int price,
            uint startedAt,
            uint timeStamp,
            uint80 answeredInRound
        ) = priceFeed.latestRoundData();
        price = price / 10 ** 6; // get BNB price in cents
        price = 1000000000000000000 / price; //calculate amount of BNB wei for one centUSD
        uint256 a = 10000000000000000000/uint256(85); //calculate amount of MyToken wei for one centUSD
        uint256 exchangeRate = a / uint256(price); //calculate _rate for crowdsale
        return int256(exchangeRate);
    }

}

I deployed both contracts before the merge and tested them and they work.
Crowdsale contract:

// SPDX-License-Identifier: MIT
pragma solidity ^0.5.5;

import "https://github.com/OpenZeppelin/openzeppelin-contracts/blob/release-v2.5.0/contracts/crowdsale/Crowdsale.sol";
import "https://github.com/OpenZeppelin/openzeppelin-contracts/blob/release-v2.5.0/contracts/token/ERC20/ERC20.sol";
import "https://github.com/OpenZeppelin/openzeppelin-contracts/blob/release-v2.5.0/contracts/crowdsale/emission/AllowanceCrowdsale.sol";
import "https://github.com/OpenZeppelin/openzeppelin-contracts/blob/release-v2.5.0/contracts/crowdsale/validation/PausableCrowdsale.sol";

contract Seedround is Crowdsale, AllowanceCrowdsale, PausableCrowdsale {

  constructor(
    uint256 _rate,
    address payable _wallet,
    ERC20 _token,
    address _tokenWallet
  )
    Crowdsale(_rate, _wallet, _token)
    AllowanceCrowdsale(_tokenWallet)
    public
  {}

}

and my pricefeed contract which fetches the price from Chainlink and calculates my "rate" for the Crowdsale contract :

// SPDX-License-Identifier: MIT
pragma solidity ^0.5.5;

import "@chainlink/contracts/src/v0.5/interfaces/AggregatorV3Interface.sol";

contract MyRate {
    
    AggregatorV3Interface internal priceFeed;

    /**
     * Network: Binance Smart Chain Testnet
     * Aggregator: BNB/USD
     * Address: 0x2514895c72f50D8bd4B4F9b1110F0D6bD2c97526
     */
    constructor() public {
        priceFeed = AggregatorV3Interface(0x2514895c72f50D8bd4B4F9b1110F0D6bD2c97526);
    }

    function getRate() public view returns (int) {
        (
            uint80 roundID,
            int price,
            uint startedAt,
            uint timeStamp,
            uint80 answeredInRound
        ) = priceFeed.latestRoundData();
        price = price / 10 ** 6; // get BNB price in cents
        price = 1000000000000000000 / price; //calculate amount of BNB wei for one centUSD
        uint256 a = 10000000000000000000/uint256(85); //calculate amount of MyToken wei for one centUSD
        uint256 exchangeRate = a / uint256(price); //calculate _rate for crowdsale
        return int256(exchangeRate);
    }
}

Both of them are tested and work, i just cant get them into one contract merged.